Cybercrooks have deployed a sophisticated man-in-the-mobile attack using the SpyEye banking Trojan toolkit.
The Trojan, which infects Windows machines, displays additional content on a targeted European bank's webpage that requests prospective marks to input their mobile phone number and the IMEI of the device. The bank customer is informed the information is needed so that a new "digital certificate" can be sent to the phone.
The so-called certificate contains the malicious executable (sms.exe) that infects Symbian-based smartphones along with another executable (SmsControl.exe) that displays a message designed to hoodwink users into believing that the only thing delivered was a digital certificate. Net security firm F-Secure detects this malware as Spitmo-A.
The European bank targeted in the attack uses SMS-based mTANs to authorise transfers. Details of how the SMS-based mTANs are delivered to the attacker are still under investigation, but preliminary research suggests that they are delivered via HTTP, and not via SMS as with an otherwise similar earlier attack that used the infamous ZeuS cybercrime toolkit.
The earlier ZeuS-based attack also used a file called SmsControl.exe as part of its payload. Presenting a Trojan as a digital certificate, one of the tricks up the sleeve of the SpyEye-based attack, also appeared in the earlier ZeuSMitmo attack. Despite these similarities, and the rumoured merger between ZeuS and SpyEye – the two biggest toolkits for banking Trojan creation – the two strains of malware are otherwise dissimilar, F-Secure reports.
More information on the SpyEye-based mobile banking Trojan attack can be found in a blog post by F-Secure here. ®